1. Field of the Invention
The present invention is related generally to internal combustion engines, and, more specifically, to a V-type, internal, combustion engine in which at least two V-type cylinder banks, each of which comprises two co-planar, V-oriented cylinders containing pistons, all of which are connected to a common crankshaft on a common, eccentric crank axis and are synchronized in such a manner that at least one of the cylinders in each of the V-type cylinder banks fires simultaneously with at least one of the cylinders in another of the V-type cylinder banks.
2. State of the Prior Art
V-twin engines are generally two-cylinder, V-type engines in which the longitudinal axes of the two cylinders form a V in a plane that is perpendicular to the crankshaft, exemplified by the engines shown in, for example, U.S. Pat. Nos. 2,111,242, 5,615,642, and 5,950,579, all of which are incorporated herein by reference. V-twin engines are commonly used to power motorcycles. In fact, such V-twin engines, which have been manufactured for many years by Harley-Davidson Motor Co., of Milwaukee, Wis., and by other engine manufacturers, have become so popular with motorcycle enthusiasts, that the V-twin shape and even the distinctive exhaust sound and rhythm of such engines, are widely regarded as highly desirable features. At the same time, it is also popular among a subset of motorcycle enthusiasts to modify or customize motorcycles, especially motorcycles manufactured by Harley-Davidson Motor Co.—-often called “Harley-type” motorcycles—to create or obtain more distinctive appearances or features than the conventional factory-produced motorcycles, while still maintaining some degree of identity or commonality with the conventional factory produced motorcycles, such as the appearance and sound of the original V-twin engine, especially the “Harley V-Twin” (trademark) engine.
An adjunct to such motorcycle customizing activities often includes modifying the V-twin engines or building or acquiring customized substitutes, usually with the goal of making them more powerful than the original factory production V-twin engines while maintaining as much as possible the appearance, sound, and rhythm characteristics of the original Harley V-Twin engines. In fact, such endeavors have spawned and encouraged the growth of secondary industries that not only design and make customized Harley-type motorcycles, but also myriad components, including modified or customized V-twin engines, for such custom motorcycle enthusiasts. However, to obtain a significant increase in power over production V-twin engines, while still maintaining substantially the same appearance and sound and that can be mounted without substantial modifications to Harley-type motorcycle frames, transmissions, and the like, has required essentially custom designing and manufacturing entire engines, which can be too time-consuming and too expensive to do on a custom basis. Therefore, there is a need and desire for a less expensive and less time-consuming way to make a large-displacement, more powerful custom motorcycle engine that has a similar appearance and substantially the same sound and rhythm as a classic V-twin engine, especially such as those manufactured by Harley-Davidson Motor Co., and that can be mounted in a Harley-type motorcycle without extensive modifications to the frame, transmission, or other components.